Can training reduce calories.

[beenatitforyears]

Not sure if this is health or training but would like to know if the following is normal or my HR monitor is wrong. Like everyone I have favourate routes that I do because they are nice. One on the NY moors is lovely on an evening. I always wear a HR monitor and burn around 1150 calories (10 miles with hills and a big arse).

I've been away from it for over a month as Ive started training for the BG round so if its not a huge hill no point. It was a nice evening tonight so just went out for a run on my old fave. My garmin tells me that my average HR is just thes same (1 or 2 beats less if anything), the time is over 5 minutes faster (got carried away on relatively flat ground and no rain) but the calories showed 820, over 300 less!!!

I have had a check back at another regular run and that I did last week (it is a big hill so allowed) and that had dropped from just over 1000 calories to just over 700 calories. Again the average HR was the same or slightly less and the time was a little quicker.

So is the HR monitor wrong or is this normal, weight is the same and routes the same, effort pretty much the same so bit confused. The only perceptable change is I am reaching that "ooh this is getting a bit hard" stage about 6 or 7 BPM earlier but then again I have been trying to keep my HR low for a month so no huge shock really.

Any HR clued up people out there?

[Hank]

I'm no HR expert, but it could be that your body's adjusting to the BG training and therefore expecting a lengthy flogging when you don the fell shoes, hence burning its precious calories more carefully. Likewise, longer, slower paced runs make shorter, quicker stuff harder, hence stuff feeling harder sooner.

Certainly in my experience of BG training earlier this year I've been goosed whenever I try a short, sharp run, but find my endurance is still good. That's probably why the L100 seems more appealing than a BOFRA series.

[Stolly]

The heart rate monitor has nothing to do with the calculation of calories on a garmin - I get calories burned figures (which I ignore completely) and don't have a heart rate monitor at all. I think the calories figure is calculated based on your age and sex as well as the distance, speed and time etc. That said last time I fiddle faddled with my garmin settings I found out that I was a female!! I didn't realise that I been wrong all these years

(theres a chance that your settings may have changed, especially if you've had to reboot the watch??)

[beenatitforyears]

Fair point, will have a look at the settings. If its only calculated on age, sex, height, weight distance etc it should have been the same. may be it is the settings have changed, will have a look tonight, thanks stolly.

The heart rate monitor has nothing to do with the calculation of calories on a garmin - I get calories burned figures (which I ignore completely) and don't have a heart rate monitor at all. I think the calories figure is calculated based on your age and sex as well as the distance, speed and time etc. That said last time I fiddle faddled with my garmin settings I found out that I was a female!! I didn't realise that I been wrong all these years

(theres a chance that your settings may have changed, especially if you've had to reboot the watch??)

[beenatitforyears]

Interesting idea and one that I tend to agree with, its just the scale of the reduction 25% is a lot but then again the body is an amazing thing.

I'm no HR expert, but it could be that your body's adjusting to the BG training and therefore expecting a lengthy flogging when you don the fell shoes, hence burning its precious calories more carefully. Likewise, longer, slower paced runs make shorter, quicker stuff harder, hence stuff feeling harder sooner.

Certainly in my experience of BG training earlier this year I've been goosed whenever I try a short, sharp run, but find my endurance is still good. That's probably why the L100 seems more appealing than a BOFRA series.

[Stagger]

Garmins tend to work on Distance and Hr not just Hr alone.
I don't pay much attention to it either.
Fewer calories in than you require = weight loss

[Theolneywayisup]

Agree with comments above.

I don't use a HR but get Calorie figure from my Garmin. If I do a mile it will give the same amount of calories used whether I have gone up Yewbarrow to start with or jogged along a flat road (I know which mile I think has used more calories!). I think its main factors are sex, age, weight and distance. From my experience the time you take has little to do with the figure it produces.

Anyway, regardless of how they calculate it, its impossible for it to be accurate, although I guess if its consistent you can at least measure one run against another.

The watch sounds like a setting or something has changed though. I get the same figure as you quoted normally i.e. about 110 a mile.

[Yaks]

Agree, it has nothing to do with HR, or even speed or sex.

From a purely physics point of view, the amount of energy required to move a certain mass a certain distance is the same irrespective of speed ( I know that doesn't sound right, you intuitively think you must burn more energy if you go faster, but you don't. The effort is more as you are burning that energy over a shorted time period, but actual energy is the same ).

If it is showing a lower figure for the same distance then your weight setting in the watch must have reduced.

[beenatitforyears]

That was my thinking of things which is why I asked the question. I light of the replies here I have had a look back through the stats and on one occasion I went out without the HRM and just used the gps and the calorie burn is there. In theGarmin blurb they claim that calories recorded are related to BPM's. It looks like the watch has lost a setting, going to investigate tonight and will report back.

Agree, it has nothing to do with HR, or even speed or sex.

From a purely physics point of view, the amount of energy required to move a certain mass a certain distance is the same irrespective of speed ( I know that doesn't sound right, you intuitively think you must burn more energy if you go faster, but you don't. The effort is more as you are burning that energy over a shorted time period, but actual energy is the same ).

If it is showing a lower figure for the same distance then your weight setting in the watch must have reduced.

[DrPatrickBarry]

I read somewhere on the web that taking a blood sample to measure the sugar content is the only accurate way of measuring calories being burnt.